与压缩真空库耦合的单模腔内三量子点中激子纠缠  

Entanglement for excitons in three quantum dots in a cavity coupled to a broadband squeezed vacuum

作　　者：谭华堂[1] 甘仲惟[1] 李高翔[1] 

机构地区：[1]华中师范大学物理科学与技术学院,武汉430079

出　　处：《物理学报》2005年第3期1178-1183,共6页Acta Physica Sinica

基　　金：国家自然科学基金 (批准号 :10 2 0 40 0 9);国家教育部优秀青年教师基金资助的课题 .~~

摘　　要：研究了与压缩真空库场耦合的单模腔中三个量子点中激子间纠缠的动力学行为 .结果表明 :如果不考虑腔模与激子吸收 ,激子演化为纯的纠缠态 .当腔场与一压缩真空库耦合时 ,激子间形成混合三模高斯纠缠态 ;在长时极限下 ,激子态为一稳定的混合三模高斯纠缠态 .通过求解激子的特征函数 ,发现激子态的纯度与纠缠不仅依赖于腔场的初态 ,并且还与库的双光子关联强度密切相关 .The dynamical behavior of purity and entanglement for excitions in three quantum dots placed in a cavity driven by a broadband squeezed vacuum is studied in the low exciton density regime. It is found that the excitions in the three quantum dots can evolve into a pure entangled state only when the dissipation of the cavity and excitions is negligible. When the injected field into the cavity is a squeezed vacuum, the excitions will be in a three-mode Gaussian entangled mixed state even in the long time limit Analytical expressions are derived showing the dependence of the purity and entanglement property of the excitions in the three quantum dots on the squeezing properties of the initial state prepared in the cavity and the strength of two-photon correlations of the squeezed vacuum injected into the cavity.

关 键 词：激子态 纠缠态 腔场 量子点 双光子 单模 极限 压缩 场耦合 初态 

分 类 号：O413.1[理学—理论物理]